A Russian Soyuz 2-1A rocket stands tall atop its Baikonur launch pad after a Tuesday morning rollout to set the stage for liftoff at 6:36 UTC on Friday with a total of 73 satellites – ranging from 600 to 1 Kilogram, including a small satellite that could become the brightest artificial object in the night sky.

The mission, aiming for three distinct orbits, will rank second for the most satellites deployed in one go.

The 46-meter tall Soyuz rocket emerged from its assembly hall at the traditional early morning hour for a short rail journey over to the launch pad at Site 31 where the vehicle was placed in its vertical position for two days of final testing ahead of fueling and liftoff. Hidden under the rocket’s payload fairing are satellites from Russia, the United States, Germany, Japan, Canada and Norway – covering various fields such as Earth observation, ship-tracking, communications, meteorology and technology demonstration.

Soyuz Payload Stack with Kanopus at the top – Photo: Roscosmos

The payload cluster is headed by the 600-Kilogram Kanopus V-IK satellite that represents the primary passenger of Friday’s mission, aiming to continue expanding the Kanopus constellation that sets out to have six satellites in orbit by the end of 2018 to form a responsive Earth observation system.

Kanopus is operated as part of Russia’s civilian Earth-observation program that comprises two major branches – the heavy Resurs imaging satellites that deliver high-resolution imagery of Earth and Kanopus, using much lighter satellites to deliver medium-resolution imagery covering a larger area for application in mapping, environmental monitoring, agriculture and disaster relief.

Kanopus with its Solar Arrays Extended – Photo: Roscosmos

The first Kanopus V satellite launched in July 2012 and was expected to be followed one year later by Kanopus-V No.2, however that satellite’s launch was pushed to allow the addition of an infrared-imaging payload to the satellite which was re-named Kanopus V-IK to highlight its infrared capability for fire and hot spot detection down to a size of five meters. In addition to the infrared payload, the satellite hosts a black-and-white imaging system achieving a 2.1-meter ground resolution and a four-band full-color imager that delivers images with a 12-meter resolution.

The secondary satellites are being launched by Glavkosmos, a subsidiary of the Roscosmos State Corporation that aims to become a major player on the global launch market by offering low-cost launch opportunities for small satellite operators on Russia’s highly reliable Soyuz launch system. Up to 120 secondary payloads are manifested by Glavkosmos for launch this year on three Soyuz missions, one from Baikonur and two from the new Vostochny Cosmodrome that opened for business in 2016.

Glavkosmos is working with Seattle-based Spaceflight for this initial Soyuz cluster mission, though aims to work directly with satellite operators to cut out the middle man that comes in the form of launch brokers for small satellite and CubeSat missions. ECM Space Technologies, headquartered in Germany, has been contracted to handle the integration of CubeSats.

The company expects to fly secondary payloads on three Soyuz missions per year with at least one flight into Sun Synchronous Orbit, the favored destination for most of the world’s imaging satellites. Glavkosmos sees direct competition in India’s Polar Satellite Launch Vehicle that set a new record for the most satellites launched on a single rocket back in February when it deployed a total of 104 satellites, only three of which were non-CubeSats.

Glavkosmos cites its advantages in competitive launch prices, Soyuz’s reliability record and high flexibility in moving payloads from mission to mission as required by customers.

The 72-satellite cluster heading into orbit on Friday comprises five microsatellites from 17 to 120 Kilograms and 67 CubeSats – seven 6U, fifty-nine 3U and one 1U for a total of 220 CubeSat Units.

Click the following images for detailed technical overviews of each individual payload:

Weighing in at 120 Kilograms is the Flying Laptop developed at the University of Stuttgart, combining a technology demonstration mission with operational application for Earth observation and ship-tracking. The satellite is outfitted with a multi-spectral imager for Earth-observation at 21.5m resolution, a 160-meter Panoramic Camera, an AIS ship-tracking platform, and OSIRIS, a laser communications terminal that could enable high-data-rate communications up to 100Mbit/s for small satellite missions. – Photo: IRS/Universität Stuttgart

The 43-Kilogram WNISAT-1R, operated by Weather News Inc, hosts a four-camera imaging system to monitor the northern latitudes along with a Global Navigation Satellite System Reflectometry Instrument for sea state measurements to deliver data for safe ship traffic through the Arctic Sea. – Image: Weathernews

TechnoSat of the University of Berlin has a launch mass of 18kg and demonstrates the TUBiX satellite platform for future operational use and tests out various technologies such as a Fluid Dynamic Actuator for attitude control via pumping liquid metal through a ring, a high-precision star tracker for small satellites, high-speed S-Band transmitters and nano reaction wheels. The satellite also hosts a DLR payload for measuring impacts of small objects. – Image: TU Berlin / DLR

NORSat-1 (<30kg) and NORSat-2 (16.7kg) are operated by the Norwegian Space Center for the collection of Automatic Identification System data to monitor ship traffic in the Norwegian territorial waters. The #1 satellite also hosts a Total Solar Irradiance radiometer for data continuation of this ‘Essential Climate Variable’ as well as a Langmuir probe for space weather measurements. NORSat-2 is equipped with a VHF Data Exchange (VDE) payload to enable the relay of Application Specific Messages. – Image: UTIAS

CICERO-1, 2 and 3 join the CICERO-6 satellite launched earlier this year to establish a constellation of 6U CubeSats gathering radio occultation measurements of Earth’s atmosphere for operational meteorology and surface remote sensing through backscattered signals from the GPS and Galileo satellite constellations. – Image: Tyvak

Corvus-BC 1 and 2 are the first two of at least ten 6U CubeSats building the Landmapper-BC constellation segment operated by AstroDigital to deliver Earth imaging data for the commercial market and to track the global economy of food production. The 11-Kilogram BC satellites, achieving a 22-meter ground resolution, will be joined by 20 Corvus-HD satellites to capture higher resolution imagery, but of smaller areas. – Image: Astro Digital

MKA-N 1 and 2 are 6U Earth-imaging CubeSats built by Dauria Aerospace for operation by Roscosmos to capture 22-meter imagery of Earth in three color bands. They are similar to the Corvus-BC satellites because both come from a former U.S.-Russian partnership that branched out into two different programs. – Photo: Dauria Aerospace

Mayak, a 3U CubeSat, is the most interesting payload of this mission for satellite observers, aiming to create an artificial star brighter than any other man-made object in orbit, even surpassing the brightness of the International Space Station. The small satellite will deploy four triangular reflectors each with a surface of four square meters to create a tetrahedral shape that will be placed into an intentional tumbling motion to create a twinkling star passing through the sky. While interesting for hobby observers, astronomers who fight to keep skies as dark as possible are not particularly happy about the crowdfunded project. – Image: CosmoMayak

NanoAce is a technology demonstration satellite built by Tyvak Nano Satellite Systems, California to test out the company’s Endeavor platform (pictured) that is available for various operational missions. The satellite is outfitted with two visible and two IR cameras as well as a cold gas propulsion system with eight thrusters. – Image: Tyvak Nano Satellite Systems

Eight Lemur-2 CubeSats are aboard the Soyuz to join Spire Global’s constellation satellites collecting ship-tracking data on a global scale for commercial distribution and measuring atmospheric profiles through GPS occultation to assist in operational meteorology. These will bring the total number of Lemur-2 satellites launched into orbit to 48, not all of which are still in orbit or operational. – Photo: Spire

Planet’s Flock-2k Doves, a total of 48 CubeSats, will be orbited by Soyuz, expanding the company’s Earth Scanner in Sun Synchronous Orbit that is capable of imaging the entire Earth once per day. Flock-2k is the second largest group of Doves orbited in one go, following up on the launch of 88 Doves in February aboard the Indian PSLV rocket to establish the Earth Scanner. – Credit: NASA

The secondary payloads are rounded up by Iskra-MAI-85, a 3U CubeSat from the Moscow Aviation Institute, and the sole 1U CubeSat of this mission, Ecuador-UTE-YuZGU – developed under a partnership by the Ecuadorian Universidad Tecnológica Equinoccial and the Russian Southwestern State University.

Photo: Roscosmos

Friday’s Soyuz/Fregat mission will be particularly complex, taking the upper stage through a roller-coaster ride to deliver the satellites to three distinct orbits followed by a targeted deorbit maneuver of the Fregat, creating a mission duration of eight hours and 42 minutes.

Liftoff is timed for precisely 6:36:49 UTC and Soyuz will depart the Baikonur Cosmodrome with a thrust of over 420 metric ton force, provided by the multi-chamber engines on the core stage and the four strap-on boosters. The boosters, each holding nearly 40 metric tons of propellant, will complete their job one minute and 58 seconds into the flight, dropping away from the still-firing core stage that will continue toward space with a thrust of 102 metric-ton force.

Hot-staging occurs four minutes and 47 seconds into the flight with ignition of the Block I third stage at the same moment pyrotechnics fire to separate the spent Block A core after it burned though 91 metric tons of propellant. Delivering 30,400-Kilogram force of thrust, the Kerosene-fueled third stage will burn for just under four minutes, accelerating the stack onto a sub-orbital trajectory. Fregat will separate from the Soyuz booster eight minutes and 49 seconds after liftoff to embark on its complex multi-orbit mission.

Fregat will be flying in its ‘M’ configuration with tank extensions to achieve the performance needed for this mission, carrying 5,250 Kilograms of self-igniting Unsymmetrical Dimethylhydrazine and Nitrogen Tetroxide for consumption by a two-metric-ton S5.92 engine. The upper stage’s mission begins shortly after separation with a propellant settling maneuver ahead of ignition of the main engine on a six-and-a-half-minute burn to place the stack into an elliptical parking orbit peaking over 500 Kilometers in altitude.

Photo: Roscosmos

Concluding its first burn, Fregat will coast for half a lap around Earth for an 86-second burn at the apogee of the orbit to serve as circularization, aiming for an orbit of 479 by 523 Kilometers, inclined 97.44 degrees for the separation of the Kanopus V-IK satellite one hour and one minute after liftoff.

Next up will be two main engine burns, both 66 seconds in duration and again spaced by half an orbit in order to achieve a near-circular orbit of 595 x 600 Kilometers for the separation of the five MicroSatellites during a 200-second sequence picking up at T+2 hours and 25 minutes. With the five MicroSats on their way, Fregat will fire up its low-thrust engines for a very slight change of the orbit, targeting 584 x 604 Kilometers for the ejection of 19 of the CubeSats (all except for the Flock 2k satellites).

After dispatching 25 of its passengers, Fregat will be headed back down, targeting a pair of orbit reduction maneuvers three hours and 15 minutes and three hours and 58 minutes into the flight with durations of 86 and 72 seconds to spiral down to an orbit of 465 x 480 Kilometers, 97.0°. What follows will be an extended period of passive flight with separation of the remaining 48 CubeSats planned over a 22.5-minute sequence seven hours and 41 minutes after launch.

The last order of business for Fregat will be a two-minute deorbit maneuver eight hours and 15 minutes after launch, placing the stage onto a sub-orbital trajectory for destructive re-entry over the Indian Ocean.